Rotors mounted on a rotating shaft are generally clamped down in order to resist high torque loads and to maintain closure of the shaft-mounted components. As a result of the clamping force, distortions may be transmitted to the rotor face since the mounting surfaces may not be uniform, rigid, or perfectly square to the shaft axis. These distortions are often referred to as “coning.” However, for correct or proper operation, the rotor face should be maintained flat and square to the shaft within a few helium light bands. In addition to clamping induced distortion, rotation of the shaft and heating of the rotor from the seal ring assembly can additionally contribute to undesirable rotor distortion.